In various electronic devices such as, for example, computers, telecommunication terminals and consumer electronics, different electronic components, and in particular, semiconductor components are required that respectively provide specific functions. Electronic devices also become increasingly multifunctional and the individual functions become increasingly complex. This results in a demand for semiconductor components suitable for use in such devices, that are multifunctional and much more complex than components available today.
The properties of semiconductor components are essentially defined by the processes of manufacturing these components. Because the semiconductor components have become increasingly complex, the processes for manufacturing such semiconductor components have also become more diverse. In order to manufacture different types of electronic components, particularly semiconductor components, using a common manufacturing process, it becomes necessary to increase the number of manufacturing steps. However, this has the disadvantage that manufacturing costs, as well as error rates, increase with the number of manufacturing steps. It is therefore advantageous to develop process steps that can be used in various ways and therefore can also be used in parallel in the manufacture of different components, if so required.
Transistors with different properties, and in particular, with different operating voltages are required in semiconductor components. In this respect, it is preferred to use transistors with a relatively low threshold voltage (VTH) referred to a maximum permissible gate voltage. In applications with signaling lines, it is possible to realize small component dimensions and a transistor driver arrangement with a small overall size.
Optimized transistors with different maximum gate voltages usually require different gate oxide thicknesses. However, the threshold voltage increases with the gate oxide thickness. In order to lower this threshold voltage, it is possible to reduce the net doping in the channel region directly beneath the gate oxide. In conventional manufacturing methods, this is realized by carrying out a so-called threshold-adjust-implant. This makes it possible to adapt the net concentration of the dopants to a desired value, wherein the net concentration can be increased as well as decreased with a threshold-adjust-implant.
However, such an implant requires additional adaptation steps that increase the costs for the manufacture of transistors, and in particular, high-voltage transistors with relatively large gate oxide thicknesses.
US2005/0194648A1 discloses a semiconductor component with different transistors that have different gate oxide thicknesses, with this semiconductor component having a relatively low threshold voltage.